Off the Grid Shed-cave

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Avid hobbyist and Handyman

Intro: Off the Grid Shed-cave

Before completing my workshed/mancave, dubbed the Shed-cave, I knew I would be needing an environment in which I will be able to operate my electric power tools, charge the cordless batteries and smartphone, work late in the night, and relax with T.V and games without installing a subpanel or siphoning power from the house via an extension. It was then I decided that my epic build (a simple 12x12 shed) would not be labeled complete until it's off the grid. So I would build the shed by day (6 months working between work). And by night, like the modern researchers of our time, armed with a cup of joe and youthful (middle age) enthusiasm, I clawed my way to the computer to bravely begin my quest...Cortana, search for free energy.

Word of advice! Free energy equipment can be very pricey so please have a budget in mind. It's always best to start small and add as the need arises.

Step 1: What I Need for Free Energy

Google informed me that for a basic free energy system setup I'm going to need: a power source; something to regulate the power; something to store the power and something to convert the stored power to usable AC. In other words, I would need solar panels or/and a wind generator; a solar and wind charge controller; batteries (deep cycle preferably) and an inverter. My intention was to harness both solar and wind energy. However, since I was only able to complete the solar, from this point forward the information given will be about harnessing solar energy.

Step 2: Power Source

Before purchasing solar panels, one should determine how much energy one will need. It's the batteries that supply voltage to the inverter. Nevertheless, if the batteries are being depleted faster than they are being charged, then there will be a problem. Solar panels should be able to keep the batteries adequately charged. Because of my intended usage for the Shed-cave and my budget, I decided to go with a 12V 100w Polycrystalline panel. This would provide me with 5A of current in direct sunlight. And as I mentioned earlier, if I need more I can always add. The panel cost me on the Bay $98.34

Ps. There are other types of panels monocrystalline (more expensive) and higher panels with higher voltages 24V.

Step 3: Location of Power Source

Most people find it easier to install the panels on their roof. But owing to the location of my Shed-cave, the roof (too many trees) was just out of the question for me. Also, the panels have to be clean from time to time (panels on roof = too much work). I needed a sunny spot that was close to the shed. A spot where I would have sun both in the summer and winter months. After watching the sun rising and falling for a few days, and the consultation of my resident solar astronomer (my wife the Gardner) I choose a location just 19 ft from the shed and about 24 ft from the charge controller and batteries.The proximity is important because it helps to determine the size wires I need to efficiently transport the juice to the batteries.

I then chose 10 AWG solar wires. Research showed that 8AWG would have been ideal (bigger wire=less heat loss over the distance). But in the imperfect world of not having all the resources at one's disposal, the 10 AWG wire would have to do. If I ever decided to add 2 more panels, in parallel, to draw more current, then I will have to increase the wire size. I found 1 pair of 50ft wire with MC4 connector for $33.85 on the bay.

Next was the mounting of the panel and the laying of the wires. The panel needed to face a southerly direction because I'm in the northern hemisphere (and I thought living in the south means I was in the southern hemisphere) and it had to be angled at certain degrees each season for maximum solar rays. You can also leave it fixed at a set angle. A quick search will yield how to calculate this. I chose to adjust the panels twice a year, summer and winter. So I built a tiltable solar mount with material from Home Depot $40 + some wood scraps I had. I also bought the electrical conduits from the big box store.

Step 4: Regulating the Power

Connecting the batteries directly to the panels is a very bad idea. Your batteries will be damaged and possibly explode from overcharging without a regulator or controller. Spend a little more, and save more the long haul.

Controllers ranged from the basic 1 or two-stage controls to the middle range PWM (pulse width modulated) to best MPPT ( maximum power point tracking). The best is always more expensive. Furthermore, I needed a controller that can also handle wind energy. So I chose a 12V 400 amp, 10k watt charge controller for wind turbine and solar panels from Missouri Wind and Solar which only set me back $69.78 on the Bay.

Step 5: Storing the Power

When I first start this project, I immediately thought that a car battery will be able to work. Afterall a battery is a battery and car batteries are reasonably priced. But I was soon schooled by the Internet University. Car batteries, even though they can work, would not be adequate for long-term storage of energy. I would have to use deep cycle batteries. Of course, anything deep would mean I have to dig deep in my pocket. These batteries are rated by the amp-hours. The more amp-hour a battery can give, the more it is going to cost. I settled on a 12V 35ah battery. In fact, I bought 2 which I connected in parallel (to increase current and maintain voltage). This would theoretically double my amps but keep the battery banks at 12V. This set me back $122.95 on the Bay.

To connect 2 batteries in parallel, you connect the positive terminals together, and the negative terminals together. Then the load and/or source is connected to the positive terminal of one battery and the negative terminal of the other. I used 1/0 AWG pure copper wires for the connecting of the batteries. This ensures minimum power loss between the battery connections.

I failed to mention earlier that your voltage rating needs to remain the same throughout your devices. That is, if you are using 12v panels, you need to use a 12v controller with a12v battery array.

Step 6: Converting the DC to AC

The current up to this point is DC. In order to operate your appliances and tools, you need the convert this DC to AC. This is where an inverter comes. Inverters come in different wattage. Also, there is the continuous watt and the peak watts. For instance, a 500-watt inverter could have a peak watt of 1000. The peak would normally double (or more) the rated watts. This peak watt is important because most motor devices need to double its wattage (called a surge) at start-up. For example, a 120v 5.8 amp device needs 696 watts to run continuously (P=IV). However, it needs 1392 watts to get going.

Then there is the Pure Sine Wave, Modified Sine Wave, and the Square Wave inverter. The PSW is more expensive and should do all that you need without no problem. It's the same wave you get from the utility company or a generator. It is reported that MSW inverter causes some batteries to overheat while being charged, along with noise in some lights, and malfunctioning of some motor devices. SW is the cheapest and the most problematic of all. I'm using a Radio Shack 350W PSW inverter that I had for a number of years now. I will have to get a higher wattage PSW inverter ( 1.5kW / 3kW ) in the future.

Step 7: The Connection

Choose the best location to mount your devices. Follow the manufacturer recommendations for connecting your panels to your charge controller and the controller to the batteries. I used 10AWG wires for all my connections from the panels to the batteries. I added a Watt Meter between the solar panel and charge controller and a power meter on the inverter. This is just to monitor what is coming in and what is going out. Not necessary for the operation.

I used a breaker box and ran a couple of switches and outlet (using a power strip would work just fine). I also connected a 20w and a 5w light.

It was also recommended to add ground (earth) to the circuit. So I added 2 (1 for the shed and 1 for the solar panel) and grounded the batteries; charge controller; inverter; solar panels and breaker (pretty much anything with metal).

Step 8: Tada

One of my testing setup.

Step 9: Tada #2

That's all folks. I hope this information was of some assistance.

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50 Discussions

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SamuelV30

7 months ago

Thank you for this and the tiltable solar panel mount instructable. You have the gift of instruction, and it's greatly appreciated!

-Sam

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BobH160

9 months ago

Thanks for this. I have been planning to do a wind and solar install for my garden and have been reading about all the bits but I am a visual learning person so seeing this gives me a better insight as to what I will actually need.

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Aaaecm

9 months ago

Again, very inspiring. I want to provide power for some light applications in a fairly remote location. This would make that possible. PLEASE keep posting. Your Instructables are well written and easy to understand. Enjoy your Shed-Cave. You're doing it wrong if you don't.

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charles543

9 months ago

5A at 12V is 60W, not 100W. AWG 14 wire would be more than adequate. It is easily good up to 15A.

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GeneB21charles543

Reply 9 months ago

Charles yes 14 ga wire will handle 15 amps without melting but its about your restive line losses at 12 volts for any distance more than 10 feet or so. I run a MPPT system where I series 5 160w panels to kick the voltage up to about 70 or 80 volts keeping the amperage total to one panels worth (9 amps) thus keeping my restive losses down on smaller, cheaper wire.

I am seeing you are getting a lot of info besides mine. Cool! When you parellel your panels as with PWM the voltage stays the same but your amps add up as does your wire gage requirement.

SO MUCH TO LEARN!

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GeneB21GeneB21

Reply 9 months ago

Shoot we haven't even gotten into monocrystalline or polycrystalline panels. Thats a biggie!!!

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Born_to_buildGeneB21

Reply 9 months ago

I know, it is a topic worth exploring. What's your input? Are they worth the extra cost?

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GeneB21Born_to_build

Reply 9 months ago

Is what worth the extra cost? I have done two write up for you and lost them both. Posting here sucks! I am tired of writing so may try later, or not but here is a picture of my retirement set up at the curb. I have found an off grid spot where I can park, gathered, bought, bartered and scrounged everything I thought I would need over a three year period and will move in to start assembling it all soon as the weather breaks

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Born_to_buildGeneB21

Reply 9 months ago

My apologies Gene, I was referring to Monocrystalline panels. I know they are better and more efficient. But are they worth the extra cost?

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MichaelS440charles543

Reply 9 months ago

Interesting part of the topic. "handling" may not be the best way of looking at the needs. Interestingly, he is using a PWM charger. PWM chargers simply cut off the voltage not needed and make sure the battery is never charged above a certain voltage. The 5 amp figure is not improved on, and is the maximum.

But, if a person were to use a MPPT charger, then the maximum WATTS delivered to the charger becomes important. And a reduction of WATTS caused by resistance in the wiring can be important. So, one would need to determine the resistance, and thus voltage drop, of the wire to determine if it is lessening the total power in WATTS delivered by the panel.

I have found a solar charger from Ebay, China, MPPT , that was reasonable, but many are very expensive. And I Haven't tested this charger yet. I do think it isn't a fake though, as I looked at other reviews. I've always said that if you are limited on the number of panels you can have by some sort of sq footage, real estate, like on a boat or RV, then you should always use MPPT. But that's another topic, somewhat related.

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Born_to_buildMichaelS440

Reply 9 months ago

Whenever you have more info, please share. The cost of MPPT's is why I chose the PWN.

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GeneB21Born_to_build

Reply 9 months ago

I actully have ended up with two complete systems. PWM Bogart 12 volt with a 1k full sign inverter on the bus integrated with the buses electrical system for mobility. That was my starter system also That way if shadows fall across the 2 panels mounted in parallel on the roof I still can get output. Then in my 16ft Hallmark trailer/shop/moto hauler I have MPPT 24 volt system with 4 230 AH Everyready deep cycle 6 volt in series and 5000w continuous, 20,000 peak full sign 110vac inverter/80 amp 24vdc 4 stage battery charger/ups unit. As I said, I got a little out of hand on redundancy...bring on the apcolipse I am close to ready

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Born_to_buildcharles543

Reply 9 months ago

I Agreed. The actual panel spec: V=17.2v and A=5.81. According to the calculations, the distance from panel to the batteries should factor in the determining the size of the wires. This is important for efficiency (smaller wires generate more heat over the distance). Mine was a distance of 24ft. Also, I will be adding another panel in parallel in the future.

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steddie1

9 months ago

This is a grate 'ible! Very well-written and informative! I have been contemplating building a shed of my own, but wanted power, and wasn't too keen on working with running power from my garage, as I am not "electrical-savvy". I was always interested in off-the-grid power, but didn't think it'd be that simple. Thanks so much!

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Born_to_buildsteddie1

Reply 9 months ago

Go for it. The journey form shed-solar has been a memorable one.

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Michael Kevin Pipe

9 months ago

Thanks for the time & effort you spent teaching us. I'll be moving to Arizona this fall & leaving behind my mancave/garage. It's 24' X 24' divided down the middle , Then 1 half is divided again. #/4 tongue & groove plywood paneling (got a SUPER deal). R-19 insulation. Such a wonderful place for any man. Tools of all description, Hardwired computer desk, 100w sound system & 48" flat screen TV. And the most important? A locking door& NO windows. I will miss it terribly. So I'm taking your Mancave to heart! I will change the size a bit, increase the solar & start all over. Who says you can't teach an old dog new tricks! I've got news for them! Thanks again. (Maybe I'll post my adventure? ;-)

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IvliaV

9 months ago

Great article, but you don't have to have sunlight for 'solar' power. I recently attended our local Ideal Home show where I was looking into solar panels to make my home as much off grid as possible. I found the local installer for a new type of solar panels which were/are developed and built in France and which operate using daylight without needing sunlight (ideal as I live in Ireland where sunlight, especially in the winter, can be very elusive). I am waiting for the installer to contact me with prices etc. but they might be ideal for those who don't have access to regular sunlight, either because of where they are living or because of the position of the building eg: under trees. Hope this helps somebody can't put conventional panels up for whatever reason. Probably expensive but I was told that they are able to be taken with me when I move, are more cost effective over all because all they need is daylight - even on a winter day when it's clouds and raining outside - and have a long life span.